Logging carriage



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.1. A. PIERSON LOGGING CARRIAGE Filed Jan. 28. 1925 JIM/gr A P16115022 Wm A will mrllii 'i'l'lllt 2 Sheets-Sheet 2 INVENTOR ATTORNEY Patented June 1, 1926.

UNITED STATES JULIUS A. PIERSON, OF SEATTLE, WASHINGTON.

lnoeerue CARRIAGE.

Application filed January My invention relates to improvements in carriages of the form that are adapted to travel on trackways and carry loads and the object of my invention is to provide in a carriage of this nature, simple and. efficient means for engaging with a lifting line and holding a load in a locked position after it has been raised into a position whereby it may be carried to a desired location where it may be released automatically to lower the same.

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawings.

I accomplish these objects by devices illustrated in the accompanying drawings wherein:

Figure 1 is a View in side'elevation with parts broken away of a carriage having load holding mechanism constructed. in accordance'with my invention, said load holding mechanism being shown in an inoperative position such as it may assume while a. load is being raised.

Figures 2, 3, 4 and 5 are fragmentary views of the carriage with parts broken away showing different operative positions of the load holding means.

Figures 6 and 7 are sectional views substantially on broken lines 7-7 and 88 of Figure 1 respectively.

Figures 8, 9 and. 10 are detached isometric views of certain load holding and tripping dogs embodied in the invention.

Referring to the drawings, throughout which like reference numerals designate like parts, I show a carriage formed of two side plates,- 11, rigidly secured together in a spaced relation. Rotatably mounted between side plates, 11, are grooved track sheaves, 12, arranged to run on a track cable, 13, and other grooved sheaves, 14 and 15, over which a lifting or skidding cable, 18, may be drawn.

Tnaccordance with my invention I provide, within the lifting cable, 18, near the end to which the load is secured, a section of link chain, 20, of ordinary form, that is arranged to cooperate with lifting dogs 21, '22 and 23, in such a manner as to hold a load in an elevated position or to permit said load to be lowered at the will of the operator.

The chain, 20, constitutes a section of nonuniform shape with which certain of the lifting dogs may engage while the cable, 18, is uniform in shape and runs freely through 28, 1925. Serial No. 5,286.

the lifting dogs. Obviously the form of the section may be varied. i

The dog 21 is pivoted on a transverse bolt, 2%, above and slightly in front of the roller, 14, and said dog is made up of a heavier locking arm, 25, and a lighter trip arm, 26, arranged at an angle of less than ninety degrees relative to each other. The bottom end of the locking arm, 25, is bifurcated, as shown, to afford two pawls, 27, that Wlll fit over a chain link that is in the same plane as the carriage and will engage with the'next adjacent chain link that is in a plane transverse to the carriage. A rigid stop, 28, is provided between the side plates,11, at the rear of the dog, 21, and the end of the pawls, 27, are adapted to engage with and press against roller 1 1 when the dog 21 is supporting a load.

The dog, 22, is bifurcated at its upper end and the tripper dog, 23, is disposed between said bifurcations; The dogs 22 and 23 are both pivoted on a bolt that extends through side plates '11. The lower end of the dog 22 is also bifurcated to form pawls 31 that are adapted to fit over and look into engagement with the links of the chain 20. The lower edge of the tripper dog 23 is adapted to engage witha shoulder 32 of the dog 22 to limit the'relative movement of the dogs 22 and 23 in one direction and said tripper dog 23 is provided with an outwardly protruding lug 33 arranged to engage with a shoulder 34 on the dog to limit relative movement of said dogs in the oppositedirection. By this arrangement a limited relative movement between dogs 22- and 23 is afforded su'ificientto permit the chain 20 to lift dog 22 enough toclear said chain without moving tripper 'dog 23 as the chain is drawn thereunder in hoisting a load. The lug 33 on tripper dog 23 is arranged to engage with a. rigid stop 35 which prevents the lower ends of the tripper' dog from engaging with the chain 20. The pawls 27 and 31 on the bifurcated ends of dogs 21 and 22, respectively, arefar enough apart so that the cable 18 may move freely therebetween.

Thepawls 27 and 31 both taper on their rear side to permit them to enter freely between the limbs of the chain 20. The pulleys 14 and 15 are grooved to fit the chain as shown in Figures 6 and 7 so that said chain will always run straight and will not twist. In operation, before a load is hoisted the dogs 21, 22 and 23 will normally assume the positions shown in Figure 1, the cable 18 running freely through the spaces between the pawls 27 and 31 on the respective ends of dogs 21 and 22. As the cable is moved in the direction indicated by arrows in Fig ures 1, 2 and 3, in hoisting a load, the chain 20 will be drawn under the dogs 21 and 22 and the links that are in planes transverse to the plane of the carriage will lift said dogs into the position shown by dottedlines in Figure 2, while the dogs will drop down over each link that is in a plane parallel to the plane of the carriage. If the twisting movement is stopped while the chain 20 is under the dog 21 the pawls 27 of said dog will lit over one chain link and engage with the preceding link thus securely locking the chain against rearward movement and holding the load in a raised. position even though the hoisting line is slack. lVhen the dog 21 is holding a load it will rest against the stop 28 and the ends of pawls 27 will rest against sheave 1 f so that the load is borne jointly by stop 28 and sheave 14.

WVhen the load is to be lowered a pull is exerted on the cable 18 and the chain 20 is drawn on through the carriage as shown in Figure 3 past the dogs 21 and 22 so that said dogs drop down over the cable 18 as shown in Figure 4. The cable is then slackened and the chain 20 allowed to move back through the carriage so that it will first strike the dog 22 and swing said dog to the left thus lifting the arm 25 of dog 21 clear of the chain as shown in Figure 5. The dog 22 will continue to ride on the chain 20 as said chain moves rearwardly through the carriage, holding the dog 21 clear until the end of said chain has passed, whereupon both of said dogs 22 and 21 will drop by gravity into a vertical position as shown in Figure 1. p It will be noted that arm 25 of dog 21 is larger and heavier than arm 26 and that dog 22 is larger and heavier than tripper dog 23 so that arm 25 and dog 22 will always tend to drop by gravity into substantially vertical positions when they are not restrained from doing so.

Obviously the form of the irregularly shaped section of the hauling line as exemplified by the chain 20 may be varied so long as the shape of said section is such as to afford engagement with the dogs 21 and 22. v

From the above description it will be seen that my holding devices will support a load in an elevated position and may be released by simply pulling the hoisting cable for wardly through the carriage and then allowing it to return.

The foregoing description and accompa' nying drawings clearly disclose a preferred embodiment of my invention, but it will be understood that this disclosure is merely illustrative and that numerous changes may be made within the-scope and spirit of the following claims.

I claim:

1. In a load holding device of the class described, a carriage, sheaves in said carriage, a load lifting line carried on said sheaves, a linked chain section in said load lifting line, a pivotally mounted load holding dog having a substantially vertical bifurcated arm that fits over and is arranged to engage with said chain and having an arm that projects sidewise, a tripper dog arranged to engage beneath said last named arm, another dog having a limited pivotal movement relative to said tripper dog and having a bifurcated end that fits over and engages with said chain and a common pivot for said last named dog and said tripper arm.

2. The combination with a carriage having two sheaves, of a load lifting line operable over said sheaves, a section of chain in said load liftingline adjacent the load carryingend of the same, a bell crank shaped dog pivoted in said carriage adjacent one sheave and having a bifurcated end arranged to fit over links of said chain that are turned edgewise thereof and to engage links of said chain that are turned crosswise thereof, another dog pivotally mounted in said carriage and having a bifurcated end arranged to [it over alternate links of said chain and a tripper arm mounted on the same pivot with said last named dog and having limited movement relative thereto and arranged to en gage with an arm of said bell crank shaped dog to lift said bell crank shaped dog out of engagement with said chain where said chain is drawn through said carriage and then allowed to move back through said carriage. i

3. The combination with a carriage having sheaves, of a load lifting cable movable over said sheaves, a section of linked chain in said load lifting cable near the load attaching end, a bell crank shaped holding dog pivoted in said carriage, and having a nonbifurcated trip arm and a bifurcatedholding arm arranged for engagement with said chain, another dog pivoted in said carriage and having a bifurcated end arranged to engage with said chain and a tripper dog engaging beneath the non-bifurcated arm of sald holding dog and having a limited movement relative to said last named dog and arranged to be operated by said last named dog to lift said holding dog out of engagement with said chain.

In Witness whereof, I hereunto subscribe my name this 15th day of January, A. D.

JULIUS A. PIER SON. 

